class_docstr: Test various VIIRS-specific composites.
class_docstr_tok: ["Test","various","VIIRS-specific","composites","."]
docstr: Return fake sza dataset for DNB tests.
docstr_tok: ["Return","fake","sza","dataset","for","DNB","tests","."]
code: def sza(self, area):
      """Return fake sza dataset for DNB tests."""
      # data changes by row, sza changes by col for testing
      sza = np.zeros(area.shape) + 70.0
      sza[:, 3] += 20.0
      sza[:, 4:] += 45.0
      sza = da.from_array(sza, chunks=25)
      c02 = xr.DataArray(
          sza,
          dims=("y", "x"),
          attrs={
              "name": "solar_zenith_angle",
              "area": area,
              "start_time": datetime(2020, 1, 1, 12, 0, 0),
          },
      )
      return c02
  
file_path: satpy/satpy/tests/compositor_tests/test_viirs.py
imports: from datetime import datetime
  import dask.array
  import numpy
  import pytest
  import xarray
  from pyresample.geometry import AreaDefinition
label_desc: Use image node_id 3 for calling the TestVIIRSComposites obj's underlying member method code with example usage: obj.sza(area) and returns: c02